Means for producing pulsating fluid flow



Nov. 18, 1969 K. P. PALMER ETAL 3,478,766

MEANS FOR PRODUCING PULSATING FLUID FLOW Filed Feb. 1, 1968 6 IA g \7 a us lw I5 7 n no FIGZ.

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wwii ATTORNEYS 4' n lOa United States Patent U.S. Cl. 137-81.5 5 Claims ABSTRACT OF THE DISCLOSURE Means for producing pulsating fluid flow in an outlet comprising a fluid pressure driven mechanical oscillator, which has a passage which in one position will transmit fluid from an input to cut a constant supply to the outlet and in another position prevents such transmission so that supply to the outlet is re-established, the passage being shaped to afford, during fluid transmission therethrough, a reaction force to cause oscillation of the device.

The invention relates to means for producing, in an output passage, a pulsating flow of fluid, that is one in which regular changes in pressure take place at predetermined intervals.

The object of the invention is to provide means for this purpose in a convenient form.

In accordance with the present invention means for producing a pulsating flow of fluid in an output passage comprises a fluid pressure driven mechanical oscillator device comprising a member and spring combination, which when in one position is capable of transmitting fluid received from an input passage through the oscillator device and discharged therefrom to interfere with the steady flow of fluid between a discharge nozzle and an aligned receiving nozzle, and when in a further position cuts off the supply of fluid through the oscillator device, the arrangement being such that flow through the passage in the member creates reaction forces tending to oscillate the member and spring at a frequency related to the natural resonance frequency of the assembly, the resultant flow in the output passage, which is connected to the receiving nozzle, being a pulsating flow.

The invention will now be described with reference to the accompanying drawings in which:

FIGURES 1, 2, 3, 4 and 6 are diagrammatic views illustrating respective apparatus for producing pulsating flow or pressure responsive signals, and

FIGURE 5 is a plan view of the apparatus shown in FIGURE 4 with certain parts removed for clarity.

With reference to FIGURE 1 there is provided a mechanical oscillator device indicated at 10 comprising a blade spring 10a mounted upon a fixed support 11 carrying at its free end a member 10b, through which is formed an L-shaped passage 100 having an inlet end presented at the free end of the member 10b and having an" outlet end disposed at the side of the member. Arranged to align with the inlet end of the passage 100 is a nozzle 12 communicating through an input passage with a source of fluid at steady pressure indicated diagrammatically at 13. The outlet end of the passage 100 in the member 10b is arranged adjacent a pair of nozzles 14, 15 the former being a discharge nozzle communicating with a further source of fluid at steady pressure indicated at 16 and the nozzle 15 being a receiving nozzle, and commiinicating through an output passage with a device indicated at 17 at which pulsating flow or pressure is required.

In use, the alignment of the nozzle 12 with the inlet 3,438,766 Patented Nov. 18, 1969 ice end of the passage will cause fluid to flow along it to create a reaction force tending to deflect the member 10b. The deflection of the member 10b cuts off the flow of fluid through this passage 100, so that the member will now swing in the opposite direction under the influence of its spring to re-establish communication with the nozzle 12. Regular oscillations will thus occur and the oscillator device will tend to oscillate at the natural frequency of the blade spring and member combination 10a. As each pulse of fluid flows through the passage 10c in the member 1012, this will interrupt the steady flow of fluid from the discharge nozzle 14 to the receiving nozzle 15, thus creating a change in flow or pressure in outlet passage and thus in the device 17. It will be clear that a substantial flow in the system including the source 16 and the device 17 can be interrupted by this means.

In FIGURE 2, in addition to an oscillator device 10 which is similar to the device in FIGURE 1, and a source 16 and device 17, there is provided, between the receiving nozzle 15 and the device 17, a restricted passage 18 which communicates with the nozzle 12, so that the pulses received in the receiving nozzle 15 are transmitted to the nozzle 12 thus producing timed fluctuations in the nozzle 12 to amplify the oscillations of the spring and member combination in order to ensure that it continues to oscillate or will start from a rest position and continue to oscillate. To this end the length of the passage 18 is determined to produce any time delay that may be necessary between reception of a pulse in the receiving nozzle 15 and alignment between the nozzles 12 and the inlet end of the passage 100. The source 13 is omitted.

'In the example illustrated in FIGURE 3, there is not only provided the source 13, as shown in FIGURE 1, communicating with the nozzles 12, but there is also provided a restricted passage 18 as shown in FIGURE 2.

FIGURES 4 and 5 illustrate an arrangement similar to that of FIGURE 3 the member 10b is provided with two passages 10c, 10d which have separated entries and converge to a common outlet end adjacent to the nozzles 14, 15. Arranged opposite to the entry to the passage 100 is the nozzle 12 which communicates with the source 13. Opposite to the entry of the passage 10d is a further nozzle 18a at the end of the restricted passage 18 which in this example does not communicate with the passage between the nozzle 12 and the source 13. This arrangement ensures that there shall be no interaction between the passage communicating with the source 13 and the device 17 respectively.

The construction illustrated in FIGURE 6 has the mechanical oscillator device 10 supplied with fluid from the source 13 through the nozzle 12, and the flow through the passage 10c interrupts the flow which takes place from the source 13 through a passage 19 to the nozzle 14, and thence to the receiving nozzle 15, which in turn communicates with the device 17. Disposed opposite to the outlet end of the passage 100 however, is a further nozzle 20 which is at one end of a passage 21 to receive fluid leaving the passage 10c having interrupted flow between the nozzles 14, 15. The opposite end of the passage 21 has a nozzle 22 arranged to interrupt the flow between the nozzle 12 and the passage 10c in the member 10b of the oscillator device. This arrangement affords a means for self starting the device, since in the absence of this passage 21 it is possible for no oscillation of the spring and member 10b to take place in the event that it is deflected by the flow of fluid passing through its passage 100, the force exerted by this flow exceeding the spring force required to return it to a position to cut off the flow. The passage 21 ensures that in such an event, flow between the nozzle 12 and the entry of the passage 100 is interrupted.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. Means for producing pulsating flow of fluid in an output passage comprises a fluid pressure driven mechanical oscillator device comprising a member and spring combination, which when in one position is capable of transmitting fluid received from an input passage through the oscillator device and discharged therefrom to interfere with the steady flow of fluid between a discharge nozzle and an aligned receiving nozzle, and when in a further position cuts off the supply of fluid through the oscillator device, the arrangement being such that flow through the passage in the member creates reaction forces tending to oscillate the member and spring at a frequency related to the natural resonance frequency of the assembly, the resultant flow in the output passage, which is connected to the receiving nozzle, being a pulsating flow.

2. Means as claimed in claim 1 in which the oscillator device comprises a member mounted upon a blade spring, the other end of the blade spring being fixed, the member having an L-shaped passage through which the fluid flows in use.

3. Means as claimed in claim 1 in which there is a passage connecting the output passage with the input passage.

4. Means as claimed in claim 1 in which there is a passage connecting the output passage with a further nozzle arranged adjacent to the member of the oscillator and which can communicate with said further passage when communication between the first mentioned passage in the member and said input passage takes place, the two passages in the member communicating together at their discharge ends.

5. Means as claimed in claim 1 in which there is a further passage arranged to receive fluid from the passage in the member of the oscillator device simultaneously with interference of the flow between that discharge and receiving nozzles, said further passage terminating at its opposite end at a position such that when fluid-flows through it, the flow between the inlet passage and the passage in the oscillator device is interrupted.

References Cited UNITED STATES PATENTS 3,260,456 7/1966 Boothe 137-815 XR 3,275,015 9/1966 Meier 137-815 3,302,398 2/1967 Taplin et a1. 137-815 XR 3,333,596 8/1967 Bottone 137-815 3,410,290 11/1968 Phillips 137-815 SAMUEL SCOTT, Primary Examiner 

